21113021111 has 12 divisors (see below), whose sum is σ = 26128034352. Its totient is φ = 16704806976.

The previous prime is 21113021029. The next prime is 21113021129. The reversal of 21113021111 is 11112031112.

It is not a de Polignac number, because 21113021111 - 2¹⁸ = 21112758967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113321111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8922326 + ... + 8924691.

It is an arithmetic number, because the mean of its divisors is an integer number (2177336196).

Almost surely, 2^21113021111 is an apocalyptic number.

21113021111 is a deficient number, since it is larger than the sum of its proper divisors (5015013241).

21113021111 is a wasteful number, since it uses less digits than its factorization.

21113021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17847050 (or 17847037 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 21113021111 its reverse (11112031112), we get a palindrome (32225052223).

The spelling of 21113021111 in words is "twenty-one billion, one hundred thirteen million, twenty-one thousand, one hundred eleven".